Reflection at atomic level ?

1. Mar 14, 2008

mkbh_10

Please explain the phenomena of reflection at atomic level ?

We know that on reflection a phase change of pi occurs i/e phase difference b/w reflected & incident beam is pi , explain this phase change of pi at atomic level ? What is actually meant by phase change atomic level ?

2. Mar 14, 2008

pam

1. The phase change on reflection between two dielectrics is either pi or zero, depending on
n'-n.
2. The reflection is determined by the bulk material, and not on an "atomic level".

3. Mar 15, 2008

mkbh_10

But something must happen at atomic level , then only it will happen in bulk material

4. Mar 15, 2008

lightarrow

But in this case "the result of the sum is not the sum of the results". pam is right. Example: can you say the temperature of an atom? It's impossible because temperature is (as reflection) a collective behaviour of many atoms, so what happens to light interacting with a single atom is not the same to what happens when it interacts with many atoms. Certainly, however, something do happen to every atom: the electromagnetic wave perturbs the atom's electrons which, in turn, generate another wave; all the waves generated by the many atoms add up forming a resultant wave which has the properties you have studied. All these waves are electromagnetic fields, which have to obey Maxwell's equations; from those conditions you have the phase displacement; note that the effect is not peculiar of electromagnetic waves, but of waves in general which have to satisfy the same conditions.

Last edited: Mar 15, 2008